The aims of this study were (1) to assess the long-term effects of a collaborative care intervention for patients with depression on process of care outcomes, and (2) to describe whether case management was continued after the end of the original one-year intervention.This 24-month follow-up of a randomized controlled trial took place 12months after the end of the 1-year intervention. Data collection occurred by means of self-rating questionnaires and from medical records. We calculated linear mixed and logistic generalized estimating equation models.Of the 626 patients included at baseline, 439 (70.1%) participated in this follow-up. Intervention recipients gave higher ratings than control recipients in terms of mean overall Patient Assessment of Chronic Illness Care (PACIC) scores (3.12 vs. 2.86; P=.019), but no difference was found in medication adherence (mean Morisky score 2.59 vs. 2.65, P=.56), prescribed antidepressant medications (60.2% vs. 55.1%; P=.25), visits to the family physician (15.96 vs. 14.46, P=.58) or mental health specialist (3.01 vs. 2.94, P=.94) over the 12month follow-up period. Case management was continued for 47 (22.5%) selected intervention patients after the original intervention had ended.At 24months, intervention and control recipients had different PACIC ratings, but other process of care outcomes did not differ.The main effects of the intervention are apparent at 12months.